Swash type engine



Jan. 21, 1936.

C. G. NEVATT SWASH TYPE ENGINE Filed May 17, 1934 3 Sheets-Sheet l Jan. 21, 1935. c, G. NEVATT SWASH TYPE gammy:

Filed May 17, 19:54 3 sfieets-shee; 2

jan. 21, 1936. CIG, NEVATT 2,098,557

SWASH TYPE ENGINE -Filed May 17, 1934 3 Sheets-Sheet 3 Patented Jan. 21,1936

PATENT OFFICE SWASH TYPE ENGINE Christopher George Nevatt, Bristol, England, as-

signor to The Bristol Tramways & Carriage Company Limited, Bristol, England, a British company Application May 17, 1934, Serial No. 726,179 In Great Britain May 24, 1933 3 Claims.

This invention is for improvements in or relating to swash type engines of the kind'in which the engine shaft is provided with an inclined crank-pin on which is rotatably mounted a swash member and in which the engine connecting rods are attached by universal joints to the swash member.

Heretofore, various mechanisms have been proposed for anchoring the swash member to the engine so as to limit its bodily rotation about said engine shaft and inclined crank pin or disc, but otherwise leaving it free to move whereby reciprocatory movement is imparted to the connecting rods. An object of the present invention is to provide a simplified mechanism for producing similar results.

According to this invention, an engine of the type described is characterized in that a single gear track is anchored to a hollow swash member adjacent an outer peripheral wall thereof at a location radially remote from the crank-pin and arranged to lie in a general plane at right-angles to the crank-pin axis with which it is concentric and in that a stationary gear track in mesh with the first said gear track is anchored to the engineframe and arranged to encircle the crank-pin and to lie in a general plane at right-angles to the axis of the crank-shaft with which it is concentrio.

In a preferred constructional form of the invention, the gear tracks comprise two bevel gear wheels which are so arranged that the vertices of their pitch cones meet at the junction of the axis of the engine shaft with the axis of the inclined crank pin or disc.

The following is a description of three alternative forms of construction according to this invention as embodied in an engine of the general design described in prior specification No. 1,787,493

reference being made to the accompanying drawings, in which:

Figure 1 is a section through the engine in a plane containing the crank shaft;

Figure 2 is a section on the line 22 of Figure l;

Figure 3 is a similar view to Figure l of an alternative construction;

Figure 4 is a section on the line i4 of Figure 3;

Figure 5 is also a similar view to Figure l of yet a further modified construction; and

Figure 6 is a section on the line 66 of Figure 5.

Like reference numerals refer to like parts throughout the figures of the drawings.

As in the previous construction, the engine shaft is formed with an inclined crank pin H3 and the engine cylinders I! are arranged around the engine shaft so as to be parallel therewith. Mounted on the inclined crank pin is the swash member l2 which is in the form of a hollow cylindrical casing is having fork members I4 extending radially outwards from its cylindrical surface, 5 which fork members are connected by universal joints i5 to the engine connecting rods I6. The cylindrical casing is provided with disc end plates H which are formed with bearings l8 for embracing the inclined crank pin. The casing may 10 be formed in two or more parts to assist the assemblage thereof on the crank pin. Anchored to the interior of the box at a location remote from the crank pin, viz. at the junction between one end disc and the cylindrical casing, is a bevel gear 15 Wheel H! which is arranged to encircle the crank pin with which it is concentric. The bevel wheel is so designed that the apex of the pitch cone lies on the intersection of the axes of the inclined crank pin and the engine shaft. A sec- 20 ond bevel gear wheel 20 is arranged to engage the first said wheel, which second bevel gear wheel is carried by a spider 2| and encircles the inclined crank pin so as to be concentric with the axis of the engine shaft. with three radial arms 22 equally spaced apart, which arms pass out through slots 23 in the cylindrical wall of the casing and engage sockets 8 formed in the engine casing. The second bevel gear wheel is also so formed that the apex of 30 the pitch cone lies on the intersection of the axes of the inclined crank pin and engine shaft.

It will be appreciated with this arrangement that the bevel gear wheel attached to the swash member rolls round the gear wheel fixed to the engine 35 casing but that rotation of the swash member about the inclined axis of the crank pin is prevented.

In a modified form of construction shown in Figures 2 and 4, the inclined crank pin is pro- 40 vided at its centre with a journal 23 which is coaxial with the engine shaft, which journal is embraced by a bearing 24 carried by the aforesaid spider, whereby a more rigid structure is provided and the engagement of the two bevel gear wheels 45 is better maintained.

In yet a further modification shown in Figures 5 and 6, the first said bevel gear wheel l9 may be mounted outside said hollow cylindrical casing on a flange 25 formed at one end of the cylindrical 50 casing and the second bevel gear wheel may be mounted on the engine casing at 25 so as to encircle all the engine connecting rods. It should be appreciated, however, that as in the previous construction, the apices of the pitch cones of the The spider is provided 25 bevel gear wheels must lie on the intersection of the axes of the inclined crank pin and engine shaft.

I claim:-

1. A swash-type engine comprising a frame, a crank-shaft having an inclined crank, a plurality of cylinders surrounding the crank-shaft with their axes substantially parallel with the crankshaft, a hollow multi-part swash-member having a bearing at each side thereof rotatably mounted on the crank, a piston in each cylinder connected to the swash-member by a connecting rod, a gear- Wheel concentric with the crank within the swashmember and anchored thereto, a second gear wheel concentric with the crank-shaft within the swash-member meshing with the first gear, and means for anchoring the second gear to the engine frame.

2. A swash-type engine comprising a frame, a crank-shaft having an inclined crank, a plurality of cylinders surrounding the crank-shaft with their axes substantially parallel with the crankshaft, a hollow multi-part swash-member having a bearing at each side thereof rotatably mounted on the crank, a piston in each cylinder connected to the swash-member by a connecting rod, a spider within the swash-member having arms extending through openings in the swash-member and into openings in the engine frame, a gearwheel concentric with the crank within the swash-member and anchored thereto, and a second gear in the swash-member concentric with the crank-shaft meshing with the first gear and connected to the spider.

3. A swash-type engine comprising a frame, a crank-shaft having inclined cranks in line with each other and an intermediate portion in line with the crank-shaft, a plurality of cylinders surrounding the crank-shaft with their axes substantially parallel with the crank-shaft, a hollow multi-part swash-member having a hearing at each side thereof, each bearing being rotatably mounted on one of the cranks, a piston in each cylinder connected to the swash-member by a connecting-rod, a spider within the swash-member having a bearing for the intermediate portion of the crank-shaft, arms on the spider extending through openings in the swash-member into openings in the engine frame, a gear-wheel within the swash-member anchored thereto and concentric with the cranks, and a second gear-wheel within the swash-member connected to the spider l5 and meshing with the first gear-wheel.

CHRISTOPHER GEORGE NEVATT. 

